Effects of restriction of forefoot rocker functions by immobilisation of metatarsophalangeal joints on kinematics and kinetics during walking

ObjectiveThis study was conducted to investigate the effects of restriction of forefoot rocker (FFR) functions by immobilisation of unilateral metatarsophalangeal joints (MPJs) on kinematic and kinetic factors during walking.MethodsEighteen healthy young adults participated in this study. To immobilise the MPJs of the right leg, an aluminium sole plate (AS) was fixed on the sole of the foot. Kinematic and kinetic data were collected while each subject walked at a comfortable speed with the AS and without.ResultsIn the AS condition, the walking speed and contralateral step length were significantly decreased, and an asymmetrical centre of mass (COM) movement was observed. The range of plantarflexion motion and positive work by the ankle joint were decreased markedly during the late stance of the AS limb. In contrast, maximum hip and knee flexion angles in the swing phase of the AS limb and positive work by the bilateral hip joints over the gait cycle were increased.ConclusionsThe results suggested that MPJ immobilisation may result in marked motion limitation of ankle plantarflexion and inhibition of push-off by the ankle joint despite no restrictions on the ankle joint. These changes may interfere with gait speed and a smooth and symmetrical COM shift during walking.     

Assessment of patellar maltracking using combined static and dynamic MRI

Between January 1995 and Jul 1997, 474 patients with anterior knee pain resistant to conservative treatment were referred for MR of the knee. The MR examination consisted of routine sequences with an additional patellofemoral dynamic examination using a technique that has been developed at this institution. The dynamic study examines both knees simultaneously, with the patient supine and the quadriceps loaded. No gating or restraint apparatus is needed. Patellar subluxation or tilt was present in 188(40 %) of cases, bilateral in 104 and unilateral in 84 cases (right 39, left 45). It was classified as mild in 51 %, moderate in 39 % and severe in 10 %. Subluxation was more prevalent in females than males (42 % vs. 37 %) and this was most obvious in the severe group where 68 % were female. In 90 knees selected at random, four measurements of patellofemoral morphology were obtained using reconstructed images from a volume gradient echo sequence. These measurements were correlated with the degree of subluxation or tilt. A tibial tubercle distance greater than 20 mm, a femoral sulcus angle greater than 150 degrees, sulcus depth less than 4 mm were specific for subluxation but no measurement proved to be sufficiently sensitive to preclude a tracking study. MRI can be used to define more precisely the anatomy of the extensor mechanism and its relationship to the femur and tibia, in both a static and dynamic setting. In this way, patients with anterior knee pain can be classified more accurately and the outcomes of treatment more reliably assessed. Received: 17 September 1999; Revised: 31 January 2000; Accepted: 4 February 2000     

Analysis of gait symmetry during over-ground walking in children with autism spectrum disorder

Gait symmetry is utilized as an indicator of neurologic function. Healthy gait often exhibits minimal asymmetries, while pathological gait exhibits exaggerated asymmetries. The purpose of this study was to examine symmetry of mechanical gait parameters during over-ground walking in children with Autism Spectrum Disorder (ASD). Kinematic and kinetic data were obtained from 10 children (aged 5–12 years) with ASD. The Model Statistic procedure (α = 0.05) was used to compare gait related parameters between limbs. Analysis revealed children with ASD exhibit significant lower extremity joint position and ground reaction force asymmetries throughout the gait cycle. The observed asymmetries were unique for each subject. These data do not support previous research relative to gait symmetry in children with ASD. Many individuals with ASD do not receive physical therapy interventions, however, precision medicine based interventions emphasizing lower extremity asymmetries may improve gait function and improve performance during activities of daily living.     

An index for the evaluation of 3D masticatory cycles stability

ObjectivesTo introduce an index (Masticatory Stability Index, MSI) to analyze the stability of chewing cycles in standardized conditions and test it in a group of patients with subclinical mild temporomandibular disorder (TMD).Design23 subjects with mild subacute TMD and 21 healthy subjects were involved; they all responded to a questionnaire about signs and symptoms of TMD (ProTMDmulti) and underwent a myofunctional orofacial evaluation with scores, using the protocol of orofacial myofunctional evaluation with scores (OMES). Their mandibular kinematics was assessed with a 3D motion capture system during deliberate unilateral gum chewing. The MSI was computed synthesizing the information contained in nine kinematics parameters into a single global figure. Patients’ and controls’ MSI were compared considering the preferred and non-preferred chewing side using a 2-way ANOVA (factors: group, side).ResultsTogether with a lower total score of myofunctional orofacial status, the TMD group showed a reduced stability based on MSI (p < 0.05).ConclusionsThe MSI is an efficient method to measure the stability of the masticatory cycles. These preliminary results encourage validating the index on a larger sample. The variability in the motor behavior of chewing can impair the objectivity of its evaluations in several types of patients, including those with TMD. The MSI could be useful to complement clinical assessments, providing data for planning the rehabilitation of masticatory function in these patients.     

Direction of single obstacle circumvention in middle-aged children

When required to walk around a stationary object, adults use the location of the goal to set up their locomotor axis and obstacles presented along the locomotor axis will repel the individual towards the side that affords more space [1]. Research has yet to examine whether children can identify the locomotor axis and choose their paths accordingly. Therefore, the current study examined the factors that influence the direction in which children choose to deviate around a single obstacle and whether the presence or absence of a goal influences path selection and trajectory. Ten children (age: 7.1 years ±0.8) walked along a 9 m path and avoided a single obstacle that was located in one of three locations (midline, 15 cm to the right or 15 cm to the left). On half the trials, an end-goal was visible from the start of the path while the other half of the trials had no visible goal. The results demonstrate that: (1) children are able to perceive and move towards more open space but are more variable when the end-goal is not visible; (2) children are capable of maintaining an elliptical-shaped protective envelope when avoiding a single obstacle regardless of whether or not the locomotor axis is established; and (3) although children are capable of choosing paths that afford the most space, the manner in which they arrive at their goal is not driven by factors similar to adults.     

Subthalamic nucleus stimulation and gait in Parkinson’s Disease: a not always fruitful relationship

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) provides efficient treatment for the alleviation of motor signs in patients with advanced Parkinson’s disease (PD), but its specific effects on gait is sometimes less successful as it may even lead to an aggravation of freezing of gait. To better understand when axial symptoms can be expected to improve and when they may worsen or be resistant to STN-DBS, we propose here a narrative review that considers the recent literature evidences based on instrumental gait analysis data. Our aim is to report about the efficacy of STN-DBS on PD gait, analyzing the clinical and procedural factors involved, and discussing the strategies for optimizing such effectiveness in patients with advanced PD.     

The impact of walking devices on kinematics in patients with spastic bilateral cerebral palsy

Increased anterior pelvic and trunk tilt is a common finding in patients with bilateral cerebral palsy especially during walking with assistive devices. As previous studies demonstrate various gait alterations when using assistive devices, the assessment of surgical interventions may be biased when the patients become independent of (or dependent on) assistive devices after therapy. Furthermore, some of these patients in fact are able to walk without devices even though in daily life they prefer to use them. Consequently, for such patients the classification into GMFCS level II or III may be ambiguous. The specific aim of this study was therefore to assess the influence of the use of forearm crutches and posterior walker during walking and to set this influence in relation to outcome effects of surgical intervention studies.26 ambulatory patients with spastic bilateral CP (GMFCS II–III) were included who underwent 3D gait analysis. All patients used forearm crutches or posterior walkers in everyday life even though they were able to walk without assistive devices for short distances.Independent of the type of assistive devices, the patients walk on average with more anterior trunk tilt and pelvic tilt (7° ± 6° and 3° ± 2°) and with a maximum ankle dorsiflexion decreased by 2° (±3°) when walking with assistive devices, enhancing the mal-positioning present without device. Oppositely, the knees on average are more extended by 6° (±4°) when using the assistive devices.These effects have to be taken into account when assessing gait patterns or when monitoring the outcome after intervention as assistive devices may partially hide or exaggerate therapeutic effects.     

Effects of an ankle brace on the in vivo kinematics of patients with chronic ankle instability during walking on an inversion platform

BackgroundAs in vivo tibiotalar and subtalar joint kinematics are not currently known following the application of an ankle brace, an investigation of these kinematics may provide insight into the mechanisms of ankle braces.Research questionThis study aimed to determine the effect of an ankle brace on in vivo kinematics of patients with chronic ankle instability.MethodsEleven patients with chronic ankle instability were recruited in this study. A dual fluoroscopic imaging system and a solid modeling software were utilized to calculate the joint positions of the participants as they walked barefooted on a level platform, walked barefooted on a 15° inversion platform, and walked with an ankle brace on a 15° inversion platform. The joint positions during the three walking conditions were compared.ResultsTibiotalar joints were more inverted (pose 2, p = .004), and subtalar joints were more anteriorly translated (pose 2–6, p = .003), more plantarflexed (pose 2, p = .008; pose 3, p = .013; pose 5, p = .008; pose 6, p = .016) and more inverted (pose 1–5, p = .003; pose 6, p = .013) during barefooted walking on the inversion platform than during walking on the level platform. The inversion of subtalar joints was decreased after the brace application (pose 2–4, p = .003; pose 5, p = .004; pose 7, p = .016).SignificanceBrace application reduced the increased subtalar inversion induced by the inversion platform. Nevertheless, increased subtalar anterior translation and plantarflexion persisted after brace application. The ankle brace might be beneficial for clinical populations with increased subtalar inversion.     

Patellar resurfacing has minimal impact on in vitro tibiofemoral kinematics during deep knee flexion in total knee arthroplasty

BackgroundWhile patellar resurfacing can affect patellofemoral kinematics, the effect on tibiofemoral kinematics is unknown. We hypothesized that patellar resurfacing would affect tibiofemoral kinematics during deep knee flexion due to biomechanical alteration of the extensor mechanism.MethodsWe performed cruciate-retaining TKA in fresh-frozen human cadaveric knees (N = 5) and recorded fluoroscopic kinematics during deep knee flexion before and after the patellar resurfacing. To simulate deep knee flexion, cadaver knees were tested on a dynamic, quadriceps-driven, closed-kinetic chain simulator based on the Oxford knee rig design under loads equivalent to stair climbing. To measure knee kinematics, a 2-dimensional to 3-dimensional fluoroscopic registration technique was used. Component rotation, varus-valgus angle, and anteroposterior translation of medial and lateral contact points of the femoral component relative to the tibial component were calculated over the range of flexion.ResultsThere were no significant differences in femoral component external rotation (before patellar resurfacing: 6.6 ± 2.3°, after patellar resurfacing: 7.2 ± 1.8°, p = 0.36), and less than 1° difference in femorotibial varus-valgus angle between patellar resurfacing and non-resurfacing (p = 0.01). For both conditions, the medial and lateral femorotibial contact points moved posteriorly from 0° to 30° of flexion, but not beyond 30° of flexion. At 10° of flexion, after patellar resurfacing, the medial contact point was more anteriorly located than before patellar resurfacing.ConclusionDespite the potential for alteration of the knee extensor biomechanics, patellar resurfacing had minimal effect on tibiofemoral kinematics. Patellar resurfacing, if performed adequately, is unlikely to affect postoperative knee function.     

Influence of using knee sleeve and lateral wedge insole on knee loading among healthy individuals during stair negotiation

BackgroundFor individuals with knee osteoarthritis (OA), stair negotiation is a challenging task and the first task during which they report pain due to the high knee loading required. The use of lateral wedge insole (LWI) has been found to reduce loading in patients with OA but not to reduce pain, whereas the use of knee sleeve has been shown to result in good pain reduction. Understanding the effect of combining LWI and knee sleeve use on healthy individuals before testing on individuals with knee OA is an important step.Research questionThe current study aimed to evaluate the effect of combining the use of LWI and knee sleeve and compare the results with the application of each treatment separately and with the control condition.MethodsThis randomised cross-over study included 17 healthy participants who underwent 3D gait analysis. Participants performed ascending and descending stair activities with the following four treatment conditions: five-degree LWI, off-the-shelf knee sleeve, both LWI and knee sleeve and control condition. External knee adduction moment (EKAM) and knee frontal plane range of motion (ROM) were evaluated as primary outcomes. Repeated measure ANOVA or the Friedman test was selected based on meeting the assumption followed by multiple pairwise comparisons with Bonferroni correction.ResultsIn general, the use of LWI reduced the first peak EKAM significantly (p < 0.001) compared to the control condition in stir ascending (12% reduction) but not in stair descending (p > 0.05). Interestingly, knee sleeve use did not result in any reduction in the first peak EKAM compared to the control or any other condition. However, knee sleeve use led to a significant reduction in the knee frontal plane ROM during stair descending. The combined treatment was not superior to the LWI use when compared to control in the EKAM reduction.SignificanceCombined knee sleeve and LWI use was not superior to LWI use alone in reducing the knee loading, but it may be beneficial for individuals with knee OA since it helped in reduction of the knee frontal plane ROM during stair descending. Importantly, the effect of LWI use or any other treatment must be investigated for each different activity, and the results found in one activity must not be generalised across other activities.